Coupling device for connecting elongated hollow bodies in an assembly system

ABSTRACT

Coupling device ( 12 ) for connecting elongated hollow bodies ( 26, 28 ) in an assembly system ( 10 ), comprising: a first receiving opening ( 32 ) for receiving a first elongated hollow body ( 26 ) and a second receiving opening ( 34 ) for receiving a second elongated hollow body ( 28 ), wherein the receiving openings ( 32, 34 ) are arranged relative to one another in such a way that the first and second elongated hollow bodies ( 26, 28 ) can be coupled to one another after introduction into the respective receiving openings ( 32, 34 ).

RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.16/307,000, filed Dec. 4, 2108 which is a § 371 is a national phaseapplication of International Application Serial Number PCT/EP2017/063037filed May 30, 2017, which claims priority to German Patent ApplicationNo. 10 2016 210 799.2 filed on Jun. 16, 2016, the disclosure of which isentirely incorporated herein by reference.

BACKGROUND ART

The following disclosure relates to a coupling device for connectingelongated hollow bodies in an assembly system, and an assembly systemwhich comprises such a coupling device.

In assembly systems, elongated hollow bodies, for example in the form ofhoses, pipes or ducts, are used for a variety of purposes. Often theyare used to transport fluids, components or, when suitable lines areincluded, also power and/or data between various areas and units of theassembly system. The hollow bodies are subjected here to constant wearand must therefore be replaced regularly as part of servicing works.Since the hollow bodies are mostly routed over longer distances to orthrough the assembly system and can also take a complex route here andbe attached at several points, it can be extremely laborious toundertake such an exchange. Furthermore, in the event of wear in justone comparatively small area, the entire hollow body often has to beexchanged, which can be accordingly expensive.

A need therefore exists to improve the arrangement and maintenance ofelongated hollow bodies in an assembly system.

DISCLOSURE OF THE INVENTION

To this end a coupling device for connecting elongated hollow bodies inan assembly system is provided, comprising: a first receiving opening toreceive a first elongated hollow body and a second receiving opening toreceive a second elongated hollow body, wherein the receiving openingsare arranged relative to one another in such a way that the first andsecond elongated hollow bodies can be coupled to one another afterintroduction into the respective receiving openings.

The coupling device can generally be positioned at any position alongthe route section of the hollow bodies in the assembly system, forexample centrally between a section start and end. It is made possibleby this that two elongated hollow bodies of reduced length can be usedinstead of single hollow body extending over the entire route section.In other words, the first elongated hollow body can extend from thesection start (or from a first connection) up to the coupling device andthe second elongated hollow body can extend between the coupling deviceand the section end (or up to a second connection). The two elongatedhollow bodies can be connected by the coupling device so that acontinuous route and if applicable a continuous conveying ability offluids or components through the hollow bodies is achievable from thefirst to the second connection.

If excessive wear occurs, only the elongated hollow body that isactually affected by this has to be exchanged. The less stronglyaffected hollow bodies can remain in the assembly system for the timebeing, on the other hand. This reduces costs and increasesservice-friendliness.

An elongated hollow body can be understood to mean any hollow body withan axial extension that exceeds the cross-sectional dimensions. Hoses,pipes and elongated ducts or shafts can be cited as examples. The hollowbody is formed flexibly, for example, and can generally be manufacturedfrom a plastic material. The hollow body can further be formed in onepiece or composed of several individual components and/or layers. Inparticular, the hollow body can have a sheathing. As explained below,the elongated hollow bodies can be rivet feed-hoses or so-called rivetfeed-hose cores and the assembly system can comprise an industrial robotas well as a rivet storage unit, which can be connected by means of therivet feed-hoses and via the coupling device.

The receiving openings can have any cross-sectional profile andgenerally be formed in areas of the coupling device lying opposite oneanother. The receiving openings can further define a connection axis orbe arranged along this, wherein the hollow bodies can be introduced intothe coupling device along the connection axis to be coupled to oneanother. Coupling can be understood as a (direct or indirect) connectionof the two hollow bodies, which facilitates the continuous routeexplained above or the continuous conveying ability by means of andthrough the two hollow bodies. In particular, a contact can be createdbetween the hollow bodies in this case. According to one variant, thehollow bodies can be introduced with open ends into the respectivereceiving openings, wherein the open ends can then be coupled to oneanother and in particular brought into contact. In other words, thehollow bodies can be coupled to one another by pushing onto one anotheror at least opposing arrangement of open cross-sectional areas and/orend face areas.

A further development provides that at least one of the receivingopenings comprises an exchangeable adapter piece, which is formed toreceive an elongated hollow body with predetermined cross-sectionaldimensions.

The adapter piece can generally be formed as a separate component andarranged in the coupling device if necessary, in particular depending onthe hollow body used. To this end it can be inserted into the receivingopenings, screwed to these and connected in a positive-locking manner orotherwise detachably, so that the elongated hollow body can be pushedinto the receiving opening and the adapter piece arranged therein. Toreceive the hollow body, the adapter piece can further comprise anopening, hole or internal profile.

The adapter piece can generally be formed in one piece. The adapterpiece can also be formed in several parts and in particular in twoparts, wherein the individual constituents of the adapter piece can beselected according to the current dimensions of the hollow body andconnected to one another. The adapter piece can further be formed insuch a way and in particular (internally) profiled in such way that itencloses the associated elongated hollow body substantially in apositive-locking manner, at least in sections. The adapter piece canfurther be manufactured from a plastic material, in particular aslightly flexible material, wherein, however, substantially fixeddimensions of the adapter piece are preferred and in particular theinternal profile dimensions (i.e. no manual adjustability via threadarrangements or similar).

For example, the coupling device comprises an adapter piece perreceiving opening, wherein the adapter pieces can be formed, forexample, to receive identically dimensioned and/or profiled hollowbodies.

The adapter piece generally makes it possible for the coupling device tobe connectable flexibly to different types of elongated hollow bodieswithout other separate measures having to be taken on the couplingdevice itself. On the contrary, it can be sufficient just to select asuitable adapter piece and arrange it in the receiving opening. Thecoupling device can thus remain substantially permanently and unchangedin the assembly system, although the cross-sectional dimensions of theelongated hollow bodies may change depending on the current assemblytask (for example because rivets of different sizes have to betransported by means of the hollow bodies). This increases theflexibility of the assembly system and reduces the conversion outlay,while the advantages generally achievable with the coupling device canbe retained (see above discussion on reduced maintenance costs etc.).

A further development provides that the coupling device furthercomprises a basic body, in which the first and second receiving openingsare formed, wherein the receiving openings are connected to one anothervia at least one connecting channel in the basic body. The basic bodycan be formed substantially in one piece or composed of severalindividual components. For example, the basic body comprises a materialthat is resistant to compressed air and possibly also not deformable. Inone variant the basic body is formed as a metal block and in particularas an aluminium block. However, the use of a plastic basic body or acombination of metal and plastic materials is also conceivable.

The connecting channel can further be formed as a hole or recess andextend between the two receiving openings in a straight line through thebasic body, for example. Overall this enables the elongated hollowbodies to be arranged reliably and correctly positioned relative to oneanother and to be connected to one another.

In this connection it can further be provided that the connectingchannel is formed, at least in sections, with a closed cross-sectionalprofile, for example rectangular or circular. This facilitates acorresponding secure arrangement and holding of the hollow bodies in thecoupling device and can, as explained below, also suppress amisorientation of the hollow bodies to one another. It can further beprovided that the connecting channel is formed along its entire length,predominantly or at least over a (cumulative) section proportion of 80%with a closed cross-sectional profile. The closed cross-sectionalprofile can thus only be interrupted locally, for example by cross boresfor sensor units or compressed air connections as explained below.

According to a specific embodiment, the coupling device can further beformed to connect the hollow bodies to one another substantially withfluidic decoupling from the environment. In other words, it can beprovided that following introduction into the receiving openings and ifapplicable into an adapter piece there, the hollow bodies can beenclosed by the coupling device in such a way that they aresubstantially sealed off from the environment. This is especiallyrelevant for variants in which the hollow bodies are acted upon by apressure medium (e.g. compressed air) and the connection by means of thecoupling device should not lead to any substantial pressure losses. By“substantially fluidic decoupling” a decoupling is to be understood inparticular that permits a pressure loss, in the event of pressure actingon the hollow bodies, of less than 20% and for example less than 10% orless than 5% across the coupling device.

A further development provides that the coupling device is formed sothat the adapter piece can only be arranged therein with predeterminedorientations. It can be provided in particular here that an area of thecoupling device provided for receiving the adapter piece, such as areceiving opening, for example, a possible clamping device explainedbelow and/or the connecting channel, is formed so that the adapter piececan be arranged therein only with predetermined orientations. Thecorresponding areas of the coupling device can be specially profiledand/or dimensioned for this purpose and the adapter piece can comprisean external profile corresponding to this. The corresponding areas andin particular the receiving openings can be generally profiled in anyway in this case and have, for example, a rectangular, oval or polygonalcross-sectional profile. They can define at least one orientation of theadapter piece relative to this cross-sectional profile with which thiscannot be introduced into the receiving opening. For example, thecoupling device is formed so that the adapter piece can be introducedinto it only with a maximum of two different orientations or only with asingle orientation. The term “orientation” can refer in this case to arotational position of the adapter piece about a connection axis V ofthe coupling device, or about an orientation relative to a suitablycounterprofiled receiving area of the coupling device for the adapterpiece.

In this connection it is advantageous, furthermore, if both receivingopenings comprise an adapter piece and are formed according to one ofthe above variants. The introduction and thus also connection of bothelongated hollow bodies with a preferred orientation can be ensured bythis. In other words, it can be ensured via the design of the receivingareas of the coupling device for the adapter pieces that the adapterpieces and thus also the hollow bodies receivable therein can beintroduced into the coupling device and then coupled to one another onlywith preferred orientations relative to one another.

The elongated hollow bodies can further comprise a predeterminedcross-sectional profile and the adapter piece can comprise acorrespondingly profiled receiving area for receiving the hollow body.An especially reliable receiving of the hollow bodies in the adapterpiece can be guaranteed by this. In particular, a positive-locking andif applicable even fluidically sealing receiving in the adapter piececan be provided in this case. For example, the hollow body can be formedwith a T-profile and the adapter piece can comprise a correspondinglyshaped hole or a corresponding internal profile, which acts as areceiving area. If the adapter piece is formed in two parts, inparticular so that each individual part defines at least a part of theinternal profile of the adapter piece, the individual parts of theadapter piece can generally be assembled flexibly and matching thecurrent cross-sectional profile of the hollow body to be received.

The coupling device can additionally comprise at least one clampingdevice, which is formed to clamp at least one of the hollow bodiesand/or the adapter piece in the coupling device. The clamping forcesgenerated in this case can generally facilitate a centring in thecoupling device and/or a desired relative positioning of the hollowbodies to one another. They can also fix the hollow bodies at leasttemporarily, for example in the event of a manual exchange and“reconnection” of the hollow bodies. In addition or alternatively theclamping device can fix the hollow bodies and/or the adapter piece alsopermanently in the coupling device, in particular during ongoingoperation of the assembly system and under the possible impact of apressure medium on the hollow bodies.

The clamping device can generally be formed to build up the clampingforces only selectively (for example, following manual actuation) andotherwise to assume a clamping-force-free state. The clamping forcesthat can be provided can also be limited so that they continue to permita manual introduction and movement of the hollow bodies and/or of theadapter piece into the coupling device. Finally, the clamping forces canact generally radially and be directed for example radially inwards, forexample related to a cross section plane of the receiving openings, to aconnection axis of the coupling device and/or to the longitudinal axesof the hollow bodies.

The clamping device can further be arranged in the region of one of thereceiving openings, thus in or on one of the receiving openings, forexample.

The clamping device can also comprise a nut-thread arrangement, in whicha clamping element is received, wherein the clamping element is formedto generate radial clamping forces according to a screwing movement ofthe nut. In this variant the thread can be formed on a basic body, whichcan generally be arranged fixed and/or arranged in a receiving openingor coupled to this. The nut, on the other hand, can be arranged movablyon the thread, in particular so that it is easily accessible fromoutside the coupling device and manually adjustable. If the hollow bodyand/or the adapter piece are inserted into the receiving opening, thenut can be screwed further onto the thread, for example (“screwing down”of the nut-thread arrangement), whereby clamping forces directedradially inwards, for example, and thus in the direction of the hollowbody and/or of the adapter piece, can be generated.

The clamping element can comprise a flexibly deformable material or beproduced from this and is formed annularly, for example. The clampingelement can further be formed to constrict or expand a receiving area ofthe clamping device for the hollow body and/or the adapter pieceaccording to the screwing movement. This can be achieved in that theclamping device experiences increasing or decreasing compression in thisscrewing movement, and is thus pressed radially inwards to a differentextent. According to one variant, the clamping element comprises atleast one deformation section, which is pushed increasingly out of aninitial circumferential plane when the nut is screwed onto the threadand kinks radially inwards, so to speak.

In detail the thread can be formed on an external circumferentialsurface of a cylindrical or annular basic body of the nut-threadarrangement. In the inner region of this basic body, for example closeto the internal circumferential surface, a stop surface can further beprovided, on which the clamping element is supported. The nut can alsobe formed in the same way with a corresponding stop surface, so that theclamping element can be arranged between the two stop surfaces. If thenut is now screwed onto the thread, the distance between the stopsurfaces is reduced and the clamping element is compressed to anincreasing extent. In this case it can only escape inwards or radiallyinwards, so that it constricts a corresponding receiving area for thehollow body and/or the adapter piece and exerts clamping forces on theelements arranged therein. So-called “IP screw connections” or “systemscrew connections”, which are on the whole particularly effective, canbe provided by this.

It can also be provided that the clamping device is arranged in theconnecting channel of the basic body. In this case the clamping devicefurther comprises a pressure element, for example, which can be broughtinto contact with the hollow body and/or the adapter piece with theproduction of clamping forces. The pressure element can bespring-preloaded here (e.g. in a direction directed radially inwards),wherein the preloading force can generally be selected so that thehollow body and/or the adapter piece can continue to be moved manuallypast the pressure element. The pressure element can further be formed asa ball or roller and/or supported rotatably, in order to make pushingpast easier. Furthermore, at least two opposing pressure elements of theabove kind can be provided, in order to centre the hollow body and/orthe adapter piece in the connecting channel. For example, at least fourpressure elements are provided, which can each be brought into contactwith a different side of the hollow body and/or of the adapter piece. Itcan further be provided that at least one corresponding clamping deviceis provided on both sides of the (axial) centre of the connectingchannel along its route between the receiving openings.

It is understood that generally several clamping devices can be providedin a coupling device, wherein even clamping devices according todifferent variants can be combined. For example, it can be provided thateach receiving opening is provided with a clamping device in the form ofa nut-thread arrangement, for example, and the connecting channellikewise comprises one of the above clamping devices, for example onboth sides of its axial centre.

The coupling device can further comprise at least one sensor unit, whichdetects the passage of an element and/or fluid volume to be conveyedthrough the coupling device and for example the passage of a metalcomponent transported through the hollow body. The latter can have theform of a connecting element for assembly, such as a rivet, for example.The sensor unit, which can also be described as an indicator, canoperate capacitively or inductively for this purpose, wherein theelements (hollow body/rivet core, adapter piece) arranged between thesensor unit and the components to be conveyed comprise plasticmaterials, for example, or are produced from these. If such a componentis transported through the hollow bodies inside the coupling device(e.g. by means of compressed air), the sensor unit can detect this andgenerate a corresponding signal or a signal pulse. For example, thedetection area of the sensor unit for this is arranged in the region ofa coupling area of the adapter pieces (e.g. in the region of the axialcentre of the connecting channel). The sensor unit can also beassociated with one of the adapter pieces and/or detect a region, forexample, which lies looking in the conveying direction between thecoupling area of the adapter pieces and an (outlet) receiving opening ofthe coupling device, so that a successful passing of the coupling areacan be detected.

The signal generated by the sensor unit can accordingly indicate asuccessful conveying of a component through the coupling device and thusat least indirectly confirm a successful coupling of the hollow bodies.It can further be provided that the sensor unit or a control unit of theassembly system connected to this generates a warning signal if anexpected passage of the component is not registered or if a “constantsignal” is present, which indicates the sticking of a component in thedetection area of the sensor unit.

The coupling device can further comprise a connection area for thesupply of a pressure medium, for example in the form of a compressed airconnection, wherein the connection area can be connected to at least oneof the hollow bodies in a fluid-conducting manner The fluid-conductingconnection can take place here via holes through the adapter pieceand/or the hollow bodies. The connection area can further be provided asa hole, which extends up to the connecting channel and runs transverselyto a basic body longitudinal axis or connection axis, for example. Theconnection area can thus be formed generally in the shape of a channeland optionally comprise a thread for connecting a compressed air line.The connection area is located here, for example, in the region of anaxial centre of the connecting channel or close to a coupling area ofthe adapter pieces and/or of the hollow bodies.

It can generally be provided that an assembly system comprising thecoupling device is formed to deliver a compressed air supply via theconnection area continuously or temporarily according to operatingstates of the assembly system and/or to sensor signals of the sensorunit. The time, the duration and/or the volume of the compressed airsupplied can be selected in this case according to a detected componentpassage through the coupling device, a predetermined cycle time and/or alength of the elongated hollow bodies.

In this connection, a further development provides that the couplingdevice comprises an adapter intermediate piece, which can be arranged inthe coupling device so that at least one of the hollow bodies can beconnected in a fluid-conducting manner to the connection area via theadapter intermediate piece. The adapter intermediate piece can bearranged here adjacent to at least one adapter piece and in particularbe in contact with this. For example, the adapter intermediate piece isarranged between two adapter pieces, which each receive one of thehollow bodies, and likewise positioned in the connecting channel of thehollow body, for example. The adapter intermediate piece can furthercomprise a cavity, which is connectable in a fluid-conducting manner toat least one of the hollow bodies, in order to guarantee the compressedair supply described above. In particular, it can be provided that thecavity is formed in the shape of a channel and/or as a through-hole andhas an internal profile, for example, that corresponds substantially tothat of the hollow bodies (in particular a T-shaped profile fortransporting rivets). The adapter intermediate piece can furthercomprise an annular groove, which is connected in a fluid-conductingmanner to the compressed air connection area and from which holes extendinto the cavity, for example.

It should also be generally recorded that the term compressed air canhere also include suitable gases or gas mixtures and not only compressedambient air.

The disclosure further relates to an assembly, comprising a couplingdevice according to one of the previous claims and at least one otherexchangeable adapter piece, wherein the adapter pieces are formed toreceive hollow bodies with cross-sectional dimensions differing from oneanother.

In other words, it is provided here that the cross-sectional dimensionsof the elongated hollow bodies, which can be received by the adapterpieces, differ from one another. This assembly simplifies the conversionof the coupling device explained above in the case of changing assemblytasks, as here only the adapter pieces have to be exchanged depending onthe hollow bodies to be coupled.

The disclosure further relates to an assembly system, comprising atleast one coupling device according to one of the previous claims andtwo elongated hollow bodies, which are connectable to the couplingdevice, wherein the elongated hollow bodies are formed as supply hosesfor assembly elements to a tool unit. In this variant the hollow bodiesare accordingly formed to conduct components from a storage unit, forexample, to a tool unit. The storage and/or tool unit can be part of theassembly system or formed separately from this.

In this connection it can also be provided that the assembly elementscomprise connection elements and in particular rivets. The hollow bodiescan accordingly be rivet supply hoses, or so-called rivet cores. Thesecan generally be formed elongated and with a suitable cross-sectionalprofile (in particular T-shaped), in order to transport the rivets tothe tool unit while maintaining a preferred positional orientation.

Finally, the assembly system can also be formed to undertake the supplyof assembly elements to the tool unit under the impact of compressed airon the supply hoses. In the case of rivet supply hoses, it can thus beprovided that the rivets are moved by means of compressed air throughand along the hoses to get to the tool unit. In this connection it isparticularly advantageous if the coupling device facilitates afluidically sealing connection to the rivet hoses to be coupled, asexplained above.

The assembly system can further comprise an industrial robot with aplurality of moving robot limbs, wherein the coupling device is arrangedon one of the robot limbs. As is known, the industrial robot can beformed as a 6-axis articulated robot, wherein the robot limbs areconnected via the robot axes and are movable relative to one another.The arrangement of the coupling device directly on the industrial robotpermits arrangement close to the tool unit as well as a comparativelylarge distance to any storage unit of the assembly elements. This meansthat the particularly wear-intensive and thus frequently to be exchangedareas of the hollow body can be formed close to the tool unit ascomparatively short hollow body or hose sections, due to which theservicing and renewal costs can be kept suitably low (see also followingexplanation).

A further development provides that the robot limbs form a kinematicchain, at the end of which a connection area for the tool unit isarranged, and the coupling device is mounted on a robot limb, which isspaced by a maximum of four robot limbs from the connection area.Alternatively the coupling device can be mounted on a robot limb that isspaced by a maximum of three, two or just one robot limb from theconnection area or on the robot limb that is directly upstream of theconnection area or formed with this. In other words, this variantprovides for arrangement of the coupling device as close as possible tothe tool unit.

The inventors have recognised that in this area of the industrial robotcomparatively large movements can take place in a small space, due towhich the hollow bodies are correspondingly strongly deformed and/ormultiply deflected. This increases the wear, so that hollow bodysections running there must be exchanged comparatively early. Byarranging the coupling device in this area, it can thus be guaranteedthat a longer first hollow body, which leads to a storage unit for theassembly elements, for example, can be used for a longer period. A morestrongly deformed, shorter second hollow body, which leads from thecoupling device to the tool unit, can on the other hand be exchangedquickly and with little effort after shorter intervals. As a result thisreduces the costs, as on reaching a wear limit only the shorter, secondhollow body usually has to be exchanged, while the less stressed firsthollow body can be retained.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is to be explained with further reference tofigures. These figures show schematically:

FIG. 1 a representation of an assembly system comprising a couplingdevice according to an exemplary embodiment;

FIG. 2 a single component view of the coupling device from FIG. 1 withhollow bodies received therein;

FIGS. 3a, 3b single component views of an adapter piece of the couplingdevice from FIG. 2 in an open state and also a state enclosing thehollow body;

FIGS. 4a, 4b detail views of the coupling device according to theexemplary embodiment, which show the adapter piece taken up in a guidechannel;

FIG. 5 a detailed view of the coupling device according to the exemplaryembodiment, which shows a clamping device in the form of a nut-threadarrangement;

FIG. 6 a sectional view of the coupling device from FIG. 2 to explain asensor unit arranged therein;

FIG. 7 a sectional view of a coupling device according to anotherexemplary embodiment; and

FIG. 8 a single component view of an adapter intermediate piece of thecoupling device from FIG. 7.

DETAILED DESCRIPTION

In the following, without being restricted to these, specific detailsare described to deliver a complete understanding of the presentdisclosure. However, it is clear to a person skilled in the art that thepresent disclosure can be used in other exemplary embodiments, which maydeviate from the details described below. For example, specificconfigurations and arrangements of a coupling device and an assemblysystem are described below that should not be regarded as restrictive.Furthermore, various application areas of the coupling device areconceivable. Purely by way of example only the application forconnecting fluid-carrying hoses and cable shafts or ducts are citedhere.

A specific exemplary application area of the assembly system describedin greater detail below and its coupling device lies in the field ofautomatic assembly by means of an industrial robot, in particular forcarrying out automatic riveting processes. In these cases it is known tosupply rivets from a storage unit to a tool unit arranged on theindustrial robot via rivet supply hoses acted on by compressed air,wherein the rivet supply hoses are coupled by the coupling device.

FIG. 1 shows an assembly system 10 comprising a coupling device 12according to a first exemplary embodiment. The assembly system 10comprises an industrial robot 14, which is formed as a conventional6-axis articulated robot and comprises a plurality of robot limbs R1 toR6. These are connected to one another by the individual axes X1 to X6and are movable relative to one another. Here the robot limbs R1-R6 forman open kinematic chain, at the end of which a connection area 16 isformed, which is coupled to a riveting tool unit 18. This can insertrivets supplied to it into components in a known manner and rivet them(here shown schematically on the example of a vehicle 20).

In FIG. 1 a storage unit 22 is also recognised, in which the looserivets are taken up initially unsorted. The rivets can be separated andpositionally oriented in a preferred manner by a separating device 24 ofthe storage unit 22 (for example, by a vibrating spiral conveyor withsuitable sorting chicanes). In the case of the generally T-shapedrivets, an upright T-orientation is provided in the case shown at theoutlet of the separating device 24, wherein the rivets pass with thisorientation into an elongated hollow body in the form of a rivet supplyhose 26. As explained below, the rivet supply hose 26 is likewisesuitably T-profiled, so that the orientation of the rivets supplied canbe maintained during transportation through the hose 26.

The storage unit 22 is further formed to generate a pressure gradientbetween the separation device 24 and the tool unit 18, so that therivets are transported by compressed air through the rivet supply hose26 in the direction of the tool unit 18.

Such solutions are known in principle from the prior art. Deviating fromthese, however, the solution according to FIG. 1 provides the couplingdevice 12 to connect two individual rivet supply hoses 26, 28 on therobot 14 to one another. Put more precisely, a first rivet supply hose26 runs from the storage unit 22 and in particular the separation device24 as far as the coupling device 12 on the robot 14. A second rivetsupply hose 28 extends on the other hand from the coupling device 12along the other robot limbs R4-R6 as far as the tool unit 18.

The rivet supply hoses 26, 28 are connected to one another via thecoupling device 12 in the manner explained below so that the rivets canbe transported from the storage unit 22 continuously and withoutsubstantial air pressure loss to the tool unit 18.

Individual components and functions of the coupling device 12 areexplained in greater detail in the following with reference to the otherfigures, wherein this device is shown in some cases in differentoperating states, for example with a rivet supply hose 26, 28 receivedonly on one side. The views in the various figures can also be orienteddifferently or be from different perspectives, which can be manifestedin particular in differently shown orientations of the internalT-profiles of the rivet supply hoses 26, 28. However, it is understoodthat the following illustrations and explanations refer to one and thesame embodiment.

FIG. 2 shows the coupling device 12 in a schematic single componentrepresentation. It is recognised that the coupling device 12 comprises asolid basic body 30, which is formed here as an aluminium block. Thebasic body 30 has on opposing side wall regions a first and secondreceiving opening 32, 34 respectively, which are concealed in the viewin FIG. 2. The receiving openings 32, 34 each receive a clamping devicein the form of a nut-thread arrangement 36, which is explained in moredetail below.

It is further recognised that the receiving openings 32, 34 are arrangedrelative to one another so that they lie on a common connection axis V,which extends in a straight line through the basic body 30. In this casethe receiving openings 32, 34 are connected to one another by aconnecting channel 41 in the form of a through hole, which is likewiseexplained below.

Finally, the receiving of open ends of the rivet supply hoses 26, 28 inthe receiving openings 32, 34 is also indicated in FIG. 2. On the leftin FIG. 2 a rivet supply hose 26 is shown in the form of a so-calledunsheathed rivet core, which is formed as an elongated T-profiledplastic hollow body, which transports the rivets in the direction of thetool unit 18 while maintaining the preferred orientation. On the rightin FIG. 2, on the other hand, the rivet core is not recognisable but issheathed by a flexible material to protect it against environmentalinfluences. However, it is provided in this case also that only asimilarly formed rivet core enters the receiving opening 34 and isreceived in an adapter piece 40 arranged there (not shown). In otherwords the sheathing is targetedly removed or “stripped” at thecorresponding open end of the right rivet supply hose 28 and the rivetcore thereby exposed in this area.

It is understood that these representations are only by way of exampleand the rivet supply hoses 26, 28 can generally be formed optionally asa sheathed or unsheathed rivet core or also as a simple plastic hosewith a round profile. In either case it is further indicated in FIG. 2that the longitudinal axes L of the rivet supply hoses 26, 28 likewiserun along the connection axis V, so that the rivets can be transportedsubstantially in a straight line through the coupling device 12.

With reference to FIGS. 3a, 3b , the adapter pieces 40 received in thereceiving openings 32, 34 and clamped fixedly in the connecting channel41 are explained in more detail below. Here as an example only oneadapter piece 40 is explained, which can however be inserted inprinciple into both receiving openings 32, 34 and in which any of therivet supply hoses 26, 28 from FIG. 2 can be received.

A rivet supply hose 26, 28 formed as a T-profiled rivet core is firstrecognised in FIG. 3a . It is clear again here that the rivets can betransported with an upright T-orientation in this representation alongthe longitudinal or connection axis L, V through the rivet supply hose26, 28. It is further apparent that the adapter piece 40 is formed intwo parts and comprises two assemblable single components 42, 44. Thesingle components 42, 44 are split and assemblable along a planecontaining the longitudinal axis L of the rivet supply hose 26, 28.Furthermore, they each have an elongated inner section 46 in the form ofa recess with a rectangular profile that is open on one side. The innersections 46 each form a sub-area of an internal profile 48 of theadapter piece 40 and thus define a receiving area of the adapter piecefor the rivet supply hoses 26, 28 (see also representation of theinternal profile 48 in FIG. 4a , which is explained below).

It is further recognised that the inner section 46 of the left-handsingle component 42 in FIG. 3a is formed with a greater width B1transversely to the longitudinal or connection axis L, V than the widthB2 of the right-hand single component 44. This results in the internalprofile 48 of the assembled adapter piece 40 having a T-shaped internalcross-sectional profile corresponding to the associated rivet supplyhose 26, 28. The adapter piece 40 in the assembled state shown in FIG.3b can consequently enclose the rivet supply hose 26, 28 in apositive-locking manner It further results from FIGS. 3a, b that theadapter piece 40 is formed with an octagonal external profile.

Lastly it is recognised in FIG. 3b that the adapter piece 40 has anaxial length X along the longitudinal and connection axis L, V as wellas a connection end face 45, with which it can be coupled in the mannerdescribed below to an opposing adapter piece 40. It is provided herethat the received rivet supply hose 26, 28 is pushed far into theadapter piece 40 so that an end face of its open end 47 (cf. FIG. 3a )is aligned with the connection end face 45 of the adapter piece 40.

The arrangement of the adapter pieces 40 with the rivet supply hoses 26,28 received therein in the coupling device 12 is explained below withreference to FIGS. 4 a, b. FIG. 4a shows as an example a view throughone of the nut-thread arrangements 36 and the associated receivingopening 32, 34 from FIG. 2 in the connecting channel 41. In the opposingreceiving opening 32, 34 here an adapter piece 40 with rivet supply hose26, 28 received therein is to be recognised, which adapter piece ispushed into the connecting channel 41. The permeability or hollowformation of the rivet supply hose 26, 28 (see cavity 50 in FIG. 4a ) isrecognised again as well as the internal T-profile 48 of the adapterpiece 40 formed corresponding to its cross-sectional profile.

Clamping devices are further recognised in the side walls of theconnecting channel 41 in the form of spring-preloaded rollers 52, whichform pressure elements that can be brought into contact with the adapterpieces 40. The pressure elements 52 are positioned at respectivelyopposing positions in the side walls of the connecting channel 41 and atthe same axial height along the connection axis V, so that they canenclose an inserted adapter piece 40 uniformly. The correspondingpositions of the pressure elements 52 are indicated schematically inFIG. 4 b.

The axial position of the pressure elements 52 in the connecting channel41 is clarified further from FIG. 2. The route of the connecting channel41 is indicated schematically in this figure by dashed lines. It isrecognised that this extends with an axial length L1 in a straight linealong the connection axis V between the receiving openings 32, 34. Acentral cross-sectional plane M (or an axial centre M) of the connectingchannel 41 is marked separately here and is located at half the axiallength L1. Furthermore, two other cross-sectional planes D of theconnecting channel 41 are inserted, which lie on both sides of the axialcentre M, and are positioned in particular closer to the receivingopenings 32, 34 than to the axial centre M. Four pressure elements 52respectively are arranged in these cross-sectional planes D and arepositioned according to the FIGS. 4a, 4b in the side walls of theconnecting channel 41. Each adapter piece 40, which is introducedthrough one of the receiving openings 32, 34, is thus enclosed by arespective pressure element arrangement 52 in the cross-sectional planesD and brought into contact with these. Due to the roller shape androtatable bearing of the pressure elements 52, the adapter pieces 40 caneasily be pushed past these. At the same time, the spring preloading ofthe pressure elements 52 produces clamping forces acting radiallyinwards, however, so that the adapter pieces 40 are centred inside theconnecting channel 41.

As shown in FIG. 4b , it is further to be noted that the connectingchannel 41 has a specially shaped channel internal profile 54, in orderto avoid misorientation of the adapter pieces 40. The channel internalprofile 54 is formed rectangular in detail, wherein the corners are eachrounded to be able to receive the polygonal external profile of theadapter pieces 40. The channel internal profile consequently has twodifferent side lengths S1, S2, wherein the side length Si shown in FIG.4b slightly exceeds the side length S2. The different side lengths S1,S2 correspond to the dimensions of the external profile of the adapterpiece 40 in the manner that the adapter piece 40 can be inserted intothe coupling device 12 only with predetermined orientations. Put moreprecisely, an introduction is only possible with either the orientationindicated in FIG. 4b (internal T-profile 48 standing on its head) orwith an orientation rotated by 180° about the connection axis V (uprightinternal T-profile 48, cf. FIG. 3a ). It is understood that this appliesto both adapter pieces 40, which are introduced through the respectivereceiving openings 32, 34, so that misorientation relative to oneanother can be avoided. It is further understood that the channelinternal profile 54 can also be formed in principle so that only oneorientation of the adapter pieces 40 is possible upon take-up in theconnecting channel 41.

With reference to the figures discussed above, the mode of operation ofthe coupling device 12 is explained below. In an initial setup of theassembly system 10 or servicing taking place in the interim, suitablerivet supply hoses 26, 28 for the rivets to be transported currently arefirst selected. Depending on the cross-sectional profile of these rivetsupply hoses 26, 28, an adapter piece 40 is then selected. To this endsuitable single components 42, 44 are assembled with which a profiledinternal profile 48 matching this cross-sectional profile can be formedfor the adapter piece 40. The adapter pieces 40 with rivet supply hoses26, 28 arranged therein are then introduced through one of the receivingopenings 32, 34 respectively into the coupling device 12 and movedtowards one another along the connection axis V. Here they are centredby action of the pressure elements 52 in the respective cross-sectionalplanes D. In the region of the axial centre M of the connecting channel41, the adapter pieces 40 then meet with their connecting end faces 45,due to which the corresponding end faces of the rivet supply hoses 26,28 are also brought into contact with one another. The length X of theadapter pieces 40 is chosen here so that these extend starting out fromthe axial centre M of the connecting channel 41 up to close to thereceiving openings 32, 34 through the cross-sectional planes D and areclamped there by the pressure elements 52. Due to the positive-lockingenclosure of the rivet supply hoses 26, 28 by the adapter pieces 40 andthe enclosure of these adapter pieces 40 by the connecting channel 41,the rivets can pass over from the storage unit 22 in FIG. 1 withoutsubstantial pressure loss or other complications from the first to thesecond rivet supply hose 26, 28 and be transported to the tool unit 18.

If it is now required in the context of a change in assembly task totransport other rivets, which necessitate other rivet supply hoses 26,28, it is sufficient to select afresh and/or adapt only the adapterpieces 40, so that these can receive the differently profiled rivetsupply hoses 26, 28. The coupling device 12, on the other hand, does notneed to be adapted separately and can remain on the robot 14 withoutfurther modifications. If wear also occurs, it is usually sufficient toexchange only the shorter second rivet supply hose 28 between thecoupling device 12 and the tool unit 18, while the longer first rivetsupply hose 26 can be used over a longer period.

The above mode of operation and in particular the clamping andlow-pressure-loss connection of the rivet supply hoses 26, 28 arefurther improved by the nut-thread arrangements 36 in the receivingopenings 32, 34. From an overview of FIGS. 2 and 5 it is recognised thatthe nut-thread arrangements 36 each have an annular basic body 60, onthe outer circumferential surface of which a thread 61 is formed.Arranged on the thread 61 is a nut 62, which is movable back and forthin consequence of a screwing movement along the connection axis V. Boththe basic body 60 and the nut 62 have stop surfaces 64 axially opposingone another here on their inner circumferential surfaces, as isindicated schematically for the nut 60 in FIG. 5. When the nut 62 isscrewed onto the thread 61, the axial distance between these stopsurfaces 64 is thus reduced. A clamping element 66 is axially compressedby this and pressed radially inwards, so that the respective receivingopening 32, 34 constricts. The rivet supply hose 26, 28 received thereincan be additionally clamped by this and fluidically sealed relative tothe environment.

It is noted that in FIG. 5 the right receiving opening 34 from FIG. 2 isshown, which receives the sheathed rivet supply hose 28 and clamps andseals it by means of the nut-thread arrangement 36. As explained above,the sheathing of the rivet supply hose 28 is removed at its end, so thatthe rivet core contained therein and formed by analogy with FIGS. 3a, bis receivable directly in an adapter piece 40. On the other hand, theleft-hand nut-thread arrangement 36 shown in FIG. 2 shows that even anunsheathed rivet supply hose 28 in the form of a pure rivet core can bereceived and clamped directly in a nut-thread arrangement 36. A variantis also conceivable in which at least one of the adapter pieces 40extends from the axial centre M of the connecting channel 41 with agreater length X beyond the associated receiving opening 32, 34 and canthus likewise be received and clamped directly by a correspondingnut-thread arrangement 36.

In conclusion let reference be made further to a sensor unit 70, whichis insertable according to FIGS. 2 and 6 into a threaded through hole 72into the basic body 30 and is positioned close to the axial centre M.The sensor unit 70 is formed to detecting passing of the rivets throughthe adapter pieces 40 and the rivet cores 26, 28 received therein, whichare shown unsheathed in FIG. 6, in the region of the axial centre M. Itcan generate corresponding sensor signals, in order to provide anoperator (at least indirectly) with feedback on a successful couplingand the permeability of the rivet supply hoses 26, 28. The sensor unit70 generally detects the passage of a metal rivet through the adapterpieces 40 manufactured from plastic and the rivet supply hoses 26, 28capacitively or inductively and generates a corresponding signal pulse.If a rivet gets stuck in the detection area of the sensor unit 70, theongoing presence of this component is indicated by a correspondingconstant signal, whereupon a control unit of the assembly system, whichis not shown, can emit warning signals or adapt the air pressure in therivet supply hoses 26, 28. The same applies to the case that a sensorsignal does not materialise at a predetermined point in time and isgenerated too late or too early, which is critical for adherence topreset assembly cycle times (see also following explanation).

FIG. 6 shows two sensor units 70 as an example, which are inserted intoa respective threaded through-hole 72. However, it is also provided onlyto use one sensor unit 70. For the sake of completeness let it also bementioned that an expanded receiving area 74 of the receiving openings32, 34 is also recognised in FIG. 6, in which area the nut-threadarrangements 36, not shown in this representation, can be received. Thechannel internal profile 54 connects thereto, in order to avoid themisorientation of the adapter pieces 40 explained above.

Another embodiment of the coupling device 12 is explained with referenceto FIGS. 7 and 8, which facilitates an additional compressed air supplyinto the rivet supply hoses 26, 28. Here FIG. 7 shows a sectional view,in which the section plane contains the connection axis V. The basicbody 30 formed similarly to FIG. 6 is recognised again with theelongated connecting channel 41, which receives two adapter pieces 40with rivet supply hoses 26, 28 arranged therein. A sensor unit 70 formedsimilarly to FIG. 6 is also recognised, but which is arranged in thiscase between the axial centre M and the second rivet supply hose 28(thus between the axial centre M and the receiving opening 34 on theoutlet side viewed in the conveying direction F or between the couplingarea of the adapter pieces 40 and the corresponding receiving opening34). The sensor unit 70 can thus continue to detect whether rivets to beconveyed are transported reliably through the coupling device 12 and inparticular pass over from one rivet supply hose 26, 28 to the otherwithout malfunction.

In the region of the axial centre M, connecting channels 74 formed bycross holes are provided instead, wherein even a single such connectingchannel 74 is sufficient in principle. These channels 74 are connectedto a compressed air supply device of the assembly system 10, whichdevice is not shown, and form connection areas of the coupling device12, in order to feed compressed air continuously or temporarily into therivet supply hoses 26, 28. The coupling device 12 comprises for thispurpose an adapter intermediate piece 76, which is arranged between theadapter pieces 40 when viewed along the connection axis V and is incontact with each of these. The adapter intermediate piece 76 comprisesa channel-like cavity (not shown), which is shaped similar to theinternal T-profile of the rivet supply hoses 26, 28 and is formed as athrough-hole along the connection axis V. The adapter intermediate piece76 further has a similar external profile to the adapter pieces 40 andis thus likewise arranged with a predetermined orientation inside theconnecting channel 41.

As a result, the cavity of the adapter intermediate piece 76 aligns withthe internal profiles of the rivet supply hoses 26, 28, so that a rivetcan be transported continuously along the connection axis V and can passfrom the first rivet supply hose 26 into the cavity of the adapterintermediate piece 76 and from there into the second rivet supply hose28.

As highlighted separately in FIG. 8, the adapter intermediate piece 76further comprises an annular groove 78, which runs around an outercircumferential surface and the connection axis V. Starting out from theannular groove 78, several holes 80 extend into the profiled cavity ofthe adapter intermediate piece 76. A single such hole 80 is sufficientfor this in principle. However, as an example four holes 80 areprovided, which are distributed evenly along the annular groove 78. Asindicated by arrows L2 in FIGS. 7 and 8, compressed air can thus passvia the channels 74 and the holes 80 into the cavity of the adapterpiece 76 and via this also into the internal profiles of the rivetsupply hoses 26, 28 that are aligned with it. In particular, compressedair can be fed into the second rivet supply hose 28 leading to the toolunit 18, in order to accelerate the rivet transport.

The assembly system 10 or a control unit thereof, which is not shown,can generally be formed to activate and/or adapt the supply ofcompressed air via the connecting channels 74 or according to certainoperating states of the assembly system 10. For example, the supply ofcompressed air can be activated selectively if an unreasonably low airpressure level is detected along the transport path of the rivets.

It can likewise be generally provided to control the compressed airsupply according to sensor signals of the sensor unit 70. For example,in the event of the constant signal described above as a result of thejamming of a rivet inside the coupling device 12, the compressed airsupply can be increased temporarily. The same applies if the passage ofa rivet is detected unexpectedly late by the sensor unit 70 and therivet transport is to be accelerated. On the other hand, the compressedair supply can be reduced or interrupted if the passage of a rivet isdetected unexpectedly early. The adaptation of the compressed air supplycan take place here in particular according to a preset cycle timeand/or rivet conveying time of the assembly system 10. In addition oralternatively, a substantially continuous compressed air supply can takeplace, for example according to a total length of the conveying path ofthe rivets through the rivet supply hoses 26, 28 and the coupling device12. A pressure drop caused by route or length can be preventivelyavoided by this.

A similar compressed air supply can take place alternatively evenwithout the adapter intermediate piece 76, wherein corresponding annulargrooves and/or holes can be provided directly in at least one of theadapter pieces 40. In this case the holes can extend through the adapterpieces 40 into the internal profiles of the rivet supply hoses 26, 28 orof the rivet cores there and facilitate a continuous or temporarycompressed air supply in the same manner

Although the invention has been described with a certain degree ofparticularity, those skilled in the art can make various changes to itwithout departing from the spirit or scope of the invention ashereinafter claimed.

1. Coupling device for connecting elongated hollow bodies in an assemblysystem, comprising: a first receiving opening for receiving a firstelongated hollow body and a second receiving opening for receiving asecond elongated hollow body, wherein the receiving openings arearranged relative to one another in such a way that the first and secondelongated hollow bodies can be coupled to one another after introductioninto the respective receiving openings, and wherein the coupling deviceis formed to connect the hollow bodies to one another substantially withfluidic decoupling from the environment.
 2. Coupling device according toclaim 1, wherein at least one of the receiving openings comprises anexchangeable adapter piece, which is formed to receive an elongatedhollow body with predetermined cross-sectional dimensions.
 3. Couplingdevice according to claim 1, further comprising a basic body, in whichthe first and second receiving openings are formed, wherein thereceiving openings are connected to one another via at least oneconnecting channel in the basic body.
 4. Coupling device according toclaim 3, wherein the connecting channel is formed, at least in sections,with a closed cross-sectional profile.
 5. Coupling device according toclaim 2, wherein the coupling device is formed in such a way that theadapter piece can only be arranged therein with predeterminedorientations, in particular via a corresponding profile of at least oneof the receiving openings.
 6. Coupling device according to claim 2,wherein the elongated hollow bodies further comprise a predeterminedcross-sectional profile and the adapter piece comprises acorrespondingly profiled receiving area for receiving the hollow body.7. Coupling device according to claim 1, further comprising at least oneclamping device, which is formed to clamp at least one of the hollowbodies and/or the adapter piece fixedly in the coupling device. 8.Coupling device according to claim 7, wherein the clamping device isarranged in the area of one of the receiving openings or wherein theclamping device is arranged in the connecting channel of the basic bodyand for example further comprises a pressure element, which can bebrought into contact with the hollow body and/or the adapter piece withthe production of clamping forces.
 9. Coupling device according to claim1, further comprising a connection area for the supply of a pressuremedium, for example in the form of a compressed air connection, whereinthe connection area is connectable in a fluid-conducting manner to atleast one of the hollow bodies.
 10. Coupling device according to claim9, further comprising an adapter intermediate piece, which can bearranged in the coupling device in such a way that at least one of thehollow bodies is connectable in a fluid-conducting manner via theadapter intermediate piece to the connection area.
 11. Assembly,comprising a coupling device according to claim 2 and at least onefurther exchangeable adapter piece, wherein the adapter pieces areformed to receive hollow bodies with cross-sectional dimensionsdifferent from one another.
 12. Assembly system, comprising at least onecoupling device according to claim 1 and two elongated hollow bodies,which are connectable to the coupling device, wherein the elongatedhollow bodies are formed as supply hoses for assembly elements for atool unit.
 13. Assembly system according to claim 12, wherein theassembly elements comprise connecting elements and in particular rivetsand wherein the assembly system is formed, for example, to undertake thesupply of the assembly elements to the tool unit with a compressed airimpact on the supply hoses.
 14. Assembly system according to claim 12,comprising an industrial robot with a plurality of moving robot limbs,wherein the coupling device is arranged on one of the robot limbs and,for example, wherein the robot limbs form a kinematic chain, at the endof which a connection area is arranged for the tool unit, and thecoupling device is mounted on a robot limb, which is spaced by a maximumof four robot limbs from the connection area.